1. Field of the Invention
The present invention relates to a system and apparatus able to mechanically convey and recover fluid substances and/or solid debris floating on an uneven water surface.
2. Prior Art Background
The damage caused to the marine environment by the very huge quantities of oil which is spilled every year at sea owing to accidents of various nature to oil carriers, to production plants, to oil loading and unloading facilities, to refineries, to underwater pipelines, and so on, is well known.
The serious pollution problems represented by the massive and recurrent presence, especially inside the harbours, of enormous quantities of plastic wastes and other solid or semisolid debris are also well known.
Various types of devices are already known to try to mechanically recover these pollutants, but even though some machines are able to mechanically recover solid debris (such as with grids or the mechanical baskets) which can be considered effective, to date there does not exist any equipment really able to effectively recover fluid or semifluid pollutants floating on open waters, which are subjected to a wave-motion, such as in harbours and on the open sea.
All the conveying apparatus presently known are represented by the so-called "floating barriers" (or "booms") and by the so-called "V-shaped conveying apparatuses." Both of these conveying systems have by now widely proven to be substantially unable to produce, especially in the open sea, a conveying effect towards their center or towards one of their own extremities (in the case of the booms) or towards their own exit throat (in the case of the "V-shaped" apparatuses) of the fluid pollutant layer encountered by their entrance section.
Long experience, supported by evidence beyond doubt and evident physical considerations have demonstrated that:
a) The floating booms can be considered of some usefulness only when employed to delineate, while standstill and in calm waters, a polluted area of water, and to deflect, if correctly positioned, an oily layer floating on streaming waters with no waves (such as rivers or canals), while they cannot successfully operate when towed, e.g., by two vessels in the open sea;
b) The so-called "V-shaped" conveyors, as shown by theoretical studies as well as practical tests carried out by various authors (e.g., Cross and Hoult or J. C. Wambold and Curtiss Reed of Pennsylvania State University), are not absolutely able to do the job they ought to, since, in order to deflect and convey towards a narrower exit throat all the water which ought to enter the entrance section of such a conveying system, it would be necessary to impress to all the body of water which enters the entrance section of such a conveyor, accelerations which the "V-shaped" conveyor definitely cannot give. On the contrary, and just because of the inability of this type of conveying system to deflect and enable a flow through its throat or exit section of all the great body of water which presents itself in front of the entrance section, a strong turbulence and high pressure form in the water comprehended between the two arms, which actually pushes and deflects to the outside the greatest part of the said body of water, while the very small amount of water which some way succeeds in entering said entrance section, for the greater part will not even reach the exit section, but will escape laterally to the outside, overflowing the conveyor arms or escaping from underneath them.
Turning now to the oil mechanical recovery problem, all the oil recovery machines presently known can be basically grouped into three fundamental types, namely: the "dipping" type, the "weir" type and the "aspiration" type, all of which present specific and fundamental disadvantages, which are, respectively: a) a small oil recovery capacity; b) the impossibility of correctly positioning a weir type device in the presence of waves; and, c) the enormous amount of water which is recovered together with the oils.